1. Field of the Invention
The present invention relates to an output power control circuit, and particularly to an output power control circuit of transmission signals in a time division multiplexing access (TDMA) wireless transmitter.
2. Description of the Prior Art
Conventionally, in the TDMA wireless transmitter, there is used a transmission output control circuit for controlling the level of an output of a burst-like transmission wave and the characteristic of the leading edge and trailing edge of this output.
This sort of transmission output control circuit is disclosed in, for example, Japanese Patent Unexamined Publication No. Hei 4-100428 (JP-A-4-100428).
However, since this output power control circuit uses a nonlinear power amplifier as a transmission power amplifying circuit having a negative-feedback loop, it is difficult to control the transmission output power, particularly to control the leading edge and trailing edge of the burst-like signal waveform.
Further, since a nonlinear amplifier of an active element is inserted between a directional coupler at the output side of the transmission power amplifying circuit and a detector circuit, there are problems of current consumption, enlargement of a mounting area, and increase of cost.